Method of making shoes with shapeholding supporting frame



0:1.27, 1970 B. ROMEN v ,5 6,80

" METHOD OF MAKING SHOES WITH SHAPE-HOLDING SUPPORTING FRAME OriginalFiled June 27, 1967 i 2 Shets-Sheet 1 INVENTOR .EBvu no R om an YM/Zmm &

Rhizome/5s B. ROMEN 3,536,805

METHOD OF MAKING SHOES WITH SHAPE-HOLDING SUPPORTING FRAME Oct. 27, 1970Original Filed June 27, 1967 2 Sheets+Sheet 2 INVENTOR Bruno Rom? BY &

Hzovuess United States Patent Office Patented Oct. 27, 1970 3,536,805METHOD OF MAKING SHOES WITH SHAPE- HOLDING SUPPORTING FRAME Bruno Romen,12 Guaitastrasse, Kronberg, Taunus, Germany Original application June27, 1967, Ser. No. 649,265, now Patent No. 3,393,460, filed July 23,1968. Divided and this application May 7, 1968, Ser. No. 749,894 Claimspriority, application Germany, Apr. 19, 1967,

Int. Cl. A43b /00; A43d 65/00; B29b 7/08 US. Cl. 264-244 4 ClaimsABSTRACT OF THE DISCLOSURE A method of producing a shoe includes thesteps of placing a full length sole having a heel region and a flexiblefront part into a mold having an appropriate shape for forming a heelcap extending substantially to the arch portion of the shoe, holding aportion of an upper surface of the sole in the heel region against anupper part of said mold and spaced from a lower part and side parts ofthe mold and injecting plastic into the mold while the sole is so heldso as to mold a heel cap having lower parts extending around the lateralsides of said heel region and overlapping the lower side thereof andmolded thereto.

BACKGROUND OF THE INVENTION This application is a division ofapplication Ser. No. 649,265, filed June 27, 1967, now Pat. No.3,393,460 dated July 23, 1968.

The present invention relates to a method of constructing shoes whichprovides the shoe with a built-in shapeholding frame which consists of amolded part of plastic which is produced by injection molding andcomprises a rigid insole part which extends between the heel and ballareas of the shoe, and a heel cap which is integrally connected to thisinsole part and extends forwardly approximately to the arch portion ofthe shoe. The outer side of the supporting frame is then covered by thematerial of the upper of the shoe.

The supporting frame of a shoe of this type which may be produced in asimple manner, for example, by injection molding or casting, not onlyforms the shape-holding body of the shoe but also serves as ashape-holding support for the leather of the upper. The shaping of therear part of the upper which in previous shoe constructions had to becarried out on a heel forming machine may therefore now be omitted. Thisnot only renders the manufacture of a shoe considerably more simple andless expensive, but it also permits such a shoe to be made of a thinnerleather of a lower quality without requiring the use of an intermediatelining. Since the supporting frame may be made as a molded part ofplastic, a shoe which is provided with such a frame will have and retainthe shape of the last on which it is made much more accurately than ashoe the shape of which depends primarily upon the stability of thematerial of the upper, for example leather.

In pursuing the invention, it was found that difliculties may occur inmaking the supporting frame of a shape in accordance with the last ifthe insole part of this frame has a considerably greater thickness thanthe heel cap. Due to the difference in the length of time in which thedifferent parts of the supporting frame solidify, the danger occurs thatthe frame may be distorted by unequal shrinking of these parts.

SUMMARY OF THE INVENTION According to the invention, these difficultiesmay be substantially overcome by molding the supporting frame in such amanner upon a sole which extends along the entire length of the shoe andwill practically not shrink as the result of the molding operation thatthe supporting frame overlaps the lower side of the sole, While the partof this sole which projects forwardly from the supporting frame forms aflexible lasting sole. Aside from reducing the shrinkage, thisfull-length sole therefore has the further object to provide the shoebottom with a flexible front part which is important for permitting aproper rolling motion of the foot. The supporting frame together withthe full-length sole therefore forms a single prefabricated component.

BRIEF DESCRIPTION OF THE DRAWING to FIG. 2;

FIG. 6 shows a bottom view of the built-in part according to FIG. 2;while FIG. 7 shows a cross section which is taken along the line VIIVIIof FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in the drawings,the shoe structure according to the invention comprises a full-lengthsole 1 which consists of a flexible but shape-holding material, forexample, a fibrous synthetic-resin molded compound, which may be easilyglued together with the inner lining of the upper, not shown. The sole 1is provided within the heel area with an aperture 2 by stamping out atongue 3 which is still connected at its front end to the sole 1. Thissole is placed into the mold in the position as illustrated in FIG. 1 sothat the tongue 3 is bent downwardly and the aperture 2 is open so thatit can be filled with the plastic which forms the supporting frame.

The upper side of tongue 3, that is, the side facing the foot, isreinforced by a strip 4 of spring steel which is secured thereto andbraces the arch of the foot. When the supporting frame consisting of theheel cap 5 and the insole part 6 is being molded together with the sole1, the plastic material forming this frame will flow over the steelstrip 4 and thereby cover the same completely in the manner asillustrated in FIGS. 3 and 7.

By bending the tongue 3 downwardly, it may be pressed so firmly againstthe wall of the mold during the molding of the supporting frame that thelower side of this tongue will not be covered by plastic. The lower sideof sole 1 is therefore covered with the plastic of the supporting frameonly within the area of the marginal strip 1' which surrounds theaperture 2.

For keeping the upper side of this marginal strip 1' of sole 1 free ofplastic, this part of the sole is pressed firmly against the wall of themold while the supporting frame is being molded. The pins which areprovided in the mold to hold the tongue 3 and the marginal strip 1 inthe desired position during the molding operation leave small apertures7 in the molded product as indicated in FIGS. 5 and 6.

If the full-length sole 1 consists of a material which may be easilyglued together with the inner lining of the shoe, the upper side of themarginal strip 1 which is not covered with plastic will form a verysuitable gluing surface for securing the supporting frame to the innerlining of the shoe.

By the feature of the invention of providing the rear part of sole 1with the aperture 2, the result is attained that the plastic of thesupporting frame may also flow over the arch portion of sole 1. Thecoating 8 of plastic which is thus formed ends near the center of sole 1at a short distance from the line which forms the axis about which thesole is bent during the natural rolling motion of the foot. Thisprevents the sole 1 from breaking within this area. The coating ofplastic within the arch portion on the upper side of sole 1 has theadvantage that, due to the shrinking of the plastic while cooling, adished recess is formed which is very suitable for adapting the sole tothe shape of the foot. If the coating of plastic would not be providedon the upper side but on the lower side on sole 1, this would result ina bulging of the sole in the upward direction in deviation from theshape of the foot.

As illustrated in FIGS. 2 and 5, the front end of the plastic coating 8forms a concave are 9. The marginal parts of the plastic coating 8therefore extend farther toward the flexible part of sole 1 and therebyimprove the stability of the foot by considerably increasing the resistance of the sole against bending in the lateral directions.

As shown particularly in FIG. 4, the ball area of the sole 1 in front ofthe are 9 is likewise molded so as to have a dished shape in accordancewith the shape of this part of the bottom of the foot and thecorresponding last. This dished shape is preferably molded in the sameoperation with the molding of the supporting frame upon the sole 1 byemploying the heat and pressure of molding the latter parts also formolding the sole 1 to the desired shape.

The operation of molding the supporting frame also serves for providingthe lower side of the tongue 3 with a projection 10 to which a heel, notshown, may be subsequently secured. For producing this projection 10,tongue 3 is provided with an aperture 11 through which the plastic mayflow into a recess in the wall of the mold which has a shape inaccordance with the projection 10 so that the latter will be formedtherein. This projection 10 is preferably made of an angular blockshapeso that when the heel is fitted thereon, it will also be properlycentered.

The aperture 11 in tongue 3 coincides with an aperture 12 in the steelstrip 4 so as to permit the plastic to flow through both apertures intothe recess in the mold.

The supporting frame according to the invention preferably consists ofhigh-pressure polyethylene which possesses the desired physicalcharacteristics of this frame.

The plastic for producing the supporting frame is preferably injectedinto the mold near the rear end of sole 1, preferably at a point infront of the apex of the sole. The molecules will thereby be oriented inthe longitudinal direction of the supporting frame so that the shrinkageof the cooling plastic will have the least effect upon the desired sizeand shape of the molded article.

When employing the insert consisting of the full-length sole 1 and thesupporting frame 5, 6, there will be a change in the conventional mannerof producing the upper of the shoe insofar as the material of the upperis now drawn over the last at first at the heel area and the shoe istherefore lasted from the rear toward the front rather than vice versaas it was done previously.

Although my invention has been illustrated and described with referenceto the preferred embodiment thereof, I wish to have it understood thatit is in no way limited to the details of such embodiment but is capableof numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim 15:

1. A method of producing a shoe comprising the following steps, incombination:

'(a) placing a full length sole having a flexible front part and a heelpart which has cut into it a longitudinal tongue thus leaving a marginalstrip surrounding the tongue, and which full length sole is made of amaterial that is substantially non-shrinking under the effects ofmolding plastic to the sole into a mold of an appropriate shape forforming a heel cap extending substantially to the arch portion of theshoe;

(b) holding the sole in the mold in a position wherein the lateral edgeof the heel part of the sole is spaced from the inner surface of themold and the lower surface of the tongue and the upper surface of themarginal strip are pressed firmly againt the inner surface of the mold;and

(c) injecting a plastic into the mold, in consequence of which the lowersurface of the tongue and the upper surface of the marginal strip arekept free of plastic and there is obtained a heel cap having lower partsextending around the lateral edges of said heel part of the sole andOverlapping the lower side thereof and molded thereto.

2. The method of claim 1 including the step of forming, in the processof molding the heel cap to said sole, a ball portion on the uppersurface of said sole by means of the action of the heat and pressure ofthe molding operation so as to form a dished part in accordance with theshape of a last.

3. The method of claim 1 including the step of injecting said plasticinto the mold at a point near the rear end of said sole.

4. The method of claim 1 wherein, during plastic injection, said sole isheld to the mold with pins.

References Cited UNITED STATES PATENTS 2,483,004 9/1949 Gregg 1221 X2,607,061 8/1952 Leahy et a1 264244 X 2,764,768 10/ 1956 Ashley et al264244 X 2,912,772 11/1959 Harrison 3668 X 3,035,291 5/1962 Bingham264244 X 3,068,872 12/1962 Brody 3668 X 3,026,573 3/1962 Ciaio 264-244 XROBERT F. WHITE, Primary Examiner R. H. SHEAR, Assistant Examiner

